The PBR Workflow: How Modern Materials Are Made

9 min read · Last updated May 2026

A finished rendered sci-fi crate in the centre surrounded by its separate PBR texture map tiles — base colour, normal, roughness, metalness, and ambient occlusion
One asset, one map set. The PBR workflow is the discipline of describing a surface as separate physical properties the renderer combines.

You know that feeling when a material looks perfect in one program and plastic in another? Before PBR, that was normal — every renderer faked light differently. The PBR workflowfixed it by agreeing on the physics: describe a surface as a set of real properties, and it looks the same everywhere.

PBR isn’t one button — it’s a workflow, a way of authoring materials as separate maps that each mean something physical. This guide walks the whole thing: the two workflow flavours, the standard map set, the pipeline from model to export, and the engine quirks that trip people up.

What “PBR workflow” actually means

Physically based rendering models how light really behaves — energy conservation, Fresnel reflection, microsurface roughness. The workflow is how you feed it: instead of painting a single texture that bakes in colour, shadow, and shine, you author separate maps for each property. The colour goes in one map, the shininess in another, the bumps in a third. The renderer does the lighting. (For the concept itself, see what is PBR.)

Metalness vs specular: the two flavours

There are two standard PBR workflows, and most pipelines pick one:

  • Metal/Rough (metalness) — a greyscale metalness map flags metal versus non-metal, and the engine derives reflectance from the base colour. Simpler, less memory, harder to get wrong. The modern default in Unity, Unreal, Blender, and Godot.
  • Spec/Gloss (specular) — an RGB specular map stores reflectance colour directly, plus a glossiness map. More direct control, more memory, more room for physically impossible values.

Both describe the same physics and can match each other. Metalness won the standardisation battle because it’s leaner and more foolproof.

Two rows of rendered material spheres comparing the metalness workflow and the specular workflow, showing they can reach the same realistic results
Two workflows, same physics. Metal/rough (top) and spec/gloss (bottom) can reach identical results; metalness just uses fewer, safer maps.

The standard PBR map set

A PBR material is a stack of maps, each controlling one property:

Some add emissive (glow) and opacity (transparency). Get this set right and the material reads correctly under any lighting.

A horizontal strip of the standard PBR texture maps for a metal surface — base colour, normal, roughness, metalness, ambient occlusion, and height
The standard set: base colour, normal, roughness, metalness, AO, height. Each describes one physical property.

The texturing pipeline, step by step

  1. Model the asset (and often a high-poly version for detail).
  2. UV unwrap — lay the surface out flat with clean, non-overlapping UVs.
  3. Bake — project high-poly detail into normal, AO, and curvature maps on the low-poly.
  4. Texture — build up the surface with materials, masks, and wear, generating the full map set.
  5. Export — output the maps in your engine’s expected format, normal convention, and packing.

It’s a real craft, and for hero assets it’s worth every step. For the other 90% of surfaces — the floors, walls, props — it’s a lot of work for a tileable material.

Four stages of a 3D barrel asset shown left to right — plain grey clay model, wireframe with baked maps, textured with PBR materials, and final lit render
Model, bake, texture, render. The classic PBR pipeline for a hero asset — accurate, powerful, and slow.

Texel density and resolution

Keep texel density — texture pixels per unit of surface — consistent across a scene, or some objects look crisp next to blurry neighbours. Common targets are 1K for mobile and props, 2K for most assets, and 4K for hero close-ups. Tileable materials can be smaller because they repeat.

Channel packing: ORM and friends

To save memory, three greyscale maps are often packed into one texture’s RGB channels. The common ORM packing is Occlusion (red), Roughness (green), Metalness (blue). Unreal and most mobile pipelines use it; the data is identical, just combined. Know your engine’s expected packing before export.

The same maps, different engines

  • Unity — metalness workflow; packs metalness + smoothness (inverted roughness); OpenGL normals.
  • Unreal — metalness workflow; ORM packing common; expects DirectX normals (flip green if authored OpenGL).
  • Blender — metalness via Principled BSDF; OpenGL normals; separate map inputs.
  • Godot — metalness workflow; OpenGL normals; ORM-style packing supported.

The AI shortcut

The full pipeline is the right tool for hero assets, but it’s overkill for a tileable wood floor or a metal wall. That’s where AI collapses the workflow: describe a surface or drop a photo and get a complete, ready-to-use PBR map set in about a minute. CraftPBR outputs base colour, normal, roughness, metalness, AO, and height already matched — the same text to texture workflow, doing the map authoring for you. (See it applied in the create PBR materials with AI guide.)

Skip the pipeline for tileable surfaces
Describe a surface or drop a photo, get the full PBR map set for any engine. Free.
Open Studio →

Common PBR workflow pitfalls

  • Wrong colour space — albedo and emissive are sRGB; normal, roughness, metalness, AO, height are linear.
  • Wrong normal convention — OpenGL vs DirectX; bumps look inverted if mismatched.
  • Baked lighting in albedo — AO and shadow belong in their own maps, not the base colour.
  • Inconsistent texel density — crisp and blurry surfaces side by side.
  • Wrong channel packing — feeding an ORM texture to an engine expecting separate maps.

Key takeaways

  • The PBR workflow describes a surface as separate physical-property maps the renderer combines
  • Metal/rough is the modern default over spec/gloss — leaner and harder to get wrong
  • The core map set is albedo, normal, roughness, metalness, and AO, plus optional height
  • The classic pipeline is model → UV → bake → texture → export; AI collapses it for tileable surfaces
  • Mind colour space, normal convention, and channel packing when moving between engines
  • Keep texel density consistent so nothing looks suddenly blurry

Frequently asked questions

What is the PBR workflow?

The PBR (physically based rendering) workflow is the standard process for authoring materials that react to light realistically and look consistent across engines. You build a set of texture maps — base colour, normal, roughness, metalness, ambient occlusion — that each describe one physical property, and the renderer combines them with real-world lighting math.

What is the difference between the metalness and specular workflows?

They are two ways to author the same physics. The metal/rough (metalness) workflow uses one greyscale metalness map plus roughness, and the engine derives reflectance from the base colour — simpler and smaller. The spec/gloss (specular) workflow stores reflectance colour directly in an RGB specular map plus glossiness — more control, more memory, easier to make physically wrong. Most modern engines default to metalness.

What texture maps are in a PBR material?

The core set is base colour (albedo), normal, roughness, metalness, and ambient occlusion. Many materials add height/displacement for real depth, and some add emissive for glow or opacity for transparency. Each map controls one property, which is what makes PBR predictable across renderers.

What are the steps in a PBR texturing pipeline?

Typically: model the asset, lay out clean UVs, bake maps from a high-poly version (normal, AO, curvature), texture the surface with materials and masks, then export the map set for your engine. AI tools collapse most of this — you describe or photograph a surface and get a ready map set.

Is the PBR workflow the same in Unity, Unreal, and Blender?

The maps are the same and transfer directly, but each engine has quirks: Unreal expects DirectX normals while Blender, Unity, and Godot use OpenGL; Unity packs metalness and inverted roughness (smoothness); and engines differ on channel packing. Author once, then adjust the normal convention and packing per engine.

What is channel packing in PBR?

Channel packing stores three greyscale maps in the red, green, and blue channels of a single texture to save memory and texture samples. The common ORM packing is Occlusion in red, Roughness in green, Metalness in blue. Unreal and many mobile pipelines use it; the maps are identical, just combined into one image.

Next guide

What Is PBR? →